It may be seen by reference to the account of the 30th Ky. Infantry that in 1863 the governor of Kentucky was authorized to raise 20,000 troops for the defense of the state. The conditions rendering this necessary may also be seen in that account. Under this authority, Col. Clinton J. True, who had been an officer in the 20th Ky. Infantry, recruited the 40th Ky. Infantry.

The men were from the eastern part of the state and the regiment was mustered into the service at Grayson, Carter county, Ky., in September, 1863, to serve for twelve months. It went at once into active duty, and in November was officially reported as one of the regiments on duty in Kentucky. In the organization of the Department of the Ohio, December 31, 1863, it was in Gen. Speed S. Fry's division of Northern Central Kentucky. During the winter it was employed in scouting through the eastern part of the state. In April Gen. Hobson reported Confederate Col. Ferguson coming into Kentucky by way of Pound Gap. At that time the 40th was with Col. True, who also had under him the 11th Mich. beyond West Liberty. This force cooperating with Col. Gallup met and routed Ferguson near Paintsville, April 14th. May 30, 1854, the 40th was in Hobson's division in the 2d Brigade commanded by Col. Tue, and the regiment was in charge of its lieutenant-colonel, Matthew Mullins. In June, Gen. Morgan appeared on the Virginia side near Pound Gap. The Union troops in that section under Colonels Hanson, Gallup, John Mason Brown, and True were on the alert. But Morgan passed them and reached Mt. Sterling June 11th, near which place he overcame the forces then under Gen. Hobson, but on June 12th, the regiments under the officers just named, which had followed hard on Morgan's tracks, fought him at Cynthiana, routing him completely, and pursued him through the mountains out of the state. In this the 40th bore its part most handsomely, as the official reports show. Its effective strength on the field at that time was four hundred and fifty.

Col. Charles S. Hanson in his report expressed his most grateful thanks to the 40th Ky, along with the 39th, 37th and 52d, which were in his brigade and were with him as he says "in the fight at Cynthiana, for their bravery on the field, and efficient services rendered in the most trying hours of battle."

He especially compliments the conduct of Lieut. Col. Mullins and Maj. Bierbower of the 40th. After the rout of Morgan at Cynthiana the 40th Ky. with the brigade under Col. Hanson pursued the escaping enemy with remarkable rapidity, passing through Richmond, Irvine, Booneville, and up the south fork of Kentucky river, then crossing Pine mountain, reaching Cumberland river near Mt. Pleasant. Col. Hanson says in his report: The march of four hundred and seventy miles from Cynthiana to Cumberland river and back to Lexington in eleven days, is perhaps the most rapid and trying known in this war, especially that from Irvine to the Cumberland, a distance of one hundred and twenty miles, in less that sixty hours, with stock, the most of which had already traveled nearly one thousand miles. This route passed over the roughest road known in the Kentucky mountains, many parts of it so rough that we have to move by single file leading the horses.

In September, 1864, the 40th went with the expedition under Gen. Burbridge to Saltville, Va. The command moved through Mt. Sterling to Prestonburg, Ky., and up Louisa Fork. The mark to Saltville was attended with constant skirmishing, and as the movement became well understood by the enemy, the troops were at the salt works in sufficient number to frustrate the object of the expedition.

The place was unsuccessfully attacked October 3d, and after a severe fight Burbridge withdrew and marched all night toward Kentucky. His force consisted almost wholly of Kentucky regiments: the 40th, 13th, 35th, 45th, 26th, 30th, 11th, 37th, and 39th. Burbridge's loss in the battle of Saltville, as reported by Surg. James G Hatchitt, U.S.A., was fifty-four killed and one hundred and ninety wounded. After the return from Saltville expedition the 40th remained on duty in Eastern Kentucky until December 30, 1864, when it was mustered out of service.